Working vehicles, such as trucks, forklifts, cranes, backhoes, excavators, bulldozers, loaders and the like, oftentimes include mechanisms which may be movable with respect to one another to accomplish a function. For example, tow trucks may be fitted with beds which may be hydraulically inclined and moved to ground level to allow disabled vehicles to be loaded. As another example, forklifts will typically include forks which may be raised along masts or uprights for lifting and moving heavy objects on pallets. Integral in these vehicles is the ability to provide a mechanical movement to accomplish a function, such as lifting, digging, swinging, rotating, holding, and the like.
It is known to use hydraulic linear actuators to provide various movements on such vehicles. For example, some forklifts use a first set of hydraulic actuators for raising or lowering the forks along the masts, and a second set of hydraulic actuators for spreading the individual forks or tines, regardless of whether they have been raised or lowered. To accomplish this, an advance roll up system for hydraulic hoses is provided, so that hydraulic fluid can be provided to the second set of hydraulic actuators for spreading the forks when the first set of hydraulic actuators has raised the forks.
However, having an advance roll up of such hoses can increase costs in the system and limit visibility for the operator. In addition, having multiple hydraulic actuators and hoses also requires having multiple valves for controlling the hydraulic actuators. This can also increase costs in the system. It is therefore desirable to provide a system which can provide mechanical movements on vehicles to accomplish various functions without one or more of the aforementioned drawbacks.